1. Field of the Invention
Example embodiments of the present invention relate to a semiconductor device and methods of fabricating the same. Other example embodiments of the present invention relate to a semiconductor device having an etch stop layer and methods of fabricating the same.
2. Description of the Related Art
Generally, a MOS transistor may be used as a discrete element of a semiconductor device. In recent years, semiconductor devices have become more highly integrated. Because of the more highly integrated semiconductor devices, the MOS transistor has decreased in size. In forming contact plugs electrically connected to source/drain regions of the MOS transistor, it is known that a silicon nitride layer may function as an etch stop layer for contact holes. The silicon nitride layer may be formed on a substrate having the MOS transistor formed thereon. The prior art acknowledges that a silicon nitride layer having a relatively low stress may be used to form an etch stop layer to increase a current driving capability of an NMOS transistor.
During the formation of the etch stop layer, it may be difficult to form the etch stop layer having both a more uniform thickness and a desired stress property. In other words, even when the etch stop layer is formed having a desired stress property, problems may occur when attempting to control the thickness of the etch stop layer.
It may be desirous to fabricate a semiconductor device, including an etch stop layer with a more uniform thickness and desired stress property, having increased transistor characteristics.